One concern relating to use of rotary, impact, or percussive drilling methods when forming a wellbore is well control. A weighted or pressurized drilling fluid, such as drilling mud, may be used to provide pressure control against pressures encountered in a geological formation. Drilling mud is typically pumped toward the bottom of a wellbore using a single tubular string, then returned to the surface via the outer annulus between the tubular string and the walls of the wellbore.
While implementations are described in this disclosure by way of example, those skilled in the art will recognize that the implementations are not limited to the examples or figures described. It should be understood that the figures and detailed description thereto are not intended to limit implementations to the particular form disclosed but, on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope as defined by the appended claims. The headings used in this disclosure are for organizational purposes only and are not meant to be used to limit the scope of the description or the claims. As used throughout this application, the word “may” is used in a permissive sense (i.e., meaning having the potential to) rather than the mandatory sense (i.e., meaning must). Similarly, the words “include”, “including”, and “includes” mean “including, but not limited to”.